Expression of p24, a novel p21Waf1/Cip1/Sdi1-related protein, correlates with measurement of the finite proliferative potential of rodent embryo fibroblasts.

Normal mammalian fibroblasts undergo a limited number of divisions when cultured in vitro before entering a state of replicative senescence. The molecular basis for the determination of the finite mitotic potential is not known. Nevertheless, simian virus 40 T antigen, among other oncogenes, is able to prevent senescence in rodent embryo fibroblasts. T antigen immortalized cells are dependent upon this protein for maintaining growth once their normal mitotic life span has elapsed. Even though the mechanism that measures the finite mitotic potential of rodent fibroblasts is not known, it has been shown that it continues to function normally in the presence of this immortalizing gene. Accumulation of cyclin-dependent kinase inhibitors such as p21Waf1/Cip1/Sdi1 could potentially be a component of the mechanism that determines the finite life span. Here we show that accumulation of p21Waf1/Cip1/Sdi1 does not correlate with this biological counting mechanism, but we have identified p24, a p21Waf1/Cip1/Sdi1-related protein, whose accumulation does correlate with the measurement of the finite proliferative potential of rodent embryo fibroblasts and suggest that sequestration might be a mechanism by which its activity is regulated.

Rat embryo fibroblasts immortalized with simian virus 40 large T antigen undergo senescence upon its inactivation.

Introduction of simian virus 40 T antigen into rodent fibroblasts gives rise to cells that can proliferate indefinitely but are dependent upon it for maintenance of their growth once the normal mitotic life span has elapsed. Inactivation of T antigen in these immortalized cells causes rapid and irreversible cessation of growth. To determine whether this growth arrest is associated with entry into senescence, we have undertaken a genetic and biological analysis of conditionally immortal (tsa) cell lines derived by immortalizing rat embryo fibroblasts with the thermolabile tsA58 T antigen. This analysis has identified the following parallels between the tsa cells after inactivation of T antigen and senescent rat embryo fibroblasts: (i) growth arrest is irreversible; (ii) it occurs in G1 as well as G2; (iii) the G1 block can be partially overcome by stimulation with 20% fetal calf serum, but the G2 block cannot be overcome; (iv) 20% fetal calf serum induces c-fos, but c-myc is unaltered; and (v) fibronectin and p21(Waf1/Cip1/Sdi1) are upregulated upon growth arrest. These results suggest that T-antigen-immortalized fibroblasts are committed to undergo senescence but are prevented from undergoing this process by T antigen. Inactivation of T antigen removes this block and results in senescence of the cells. Thus, these cell lines may represent a powerful system for study of the molecular basis of entry into senescence.

Traditional veterinary medicine in India.

A tradition of veterinary therapy developed very early in India and this has survived to the present time. Based on the Ayurveda ('knowledge concerning longevity'), a medical art which had its roots in the literature of the Veda (1500-1000 BC), Indian veterinary medicine is known for its specialised literature, which provides information on ancient methods of preventing and treating diseases of animals before the advent of modern medicine. Some of these treatments, little known outside India, are still practised today.

p53 and RAS gene mutations in multiple myeloma.

We analysed genomic DNA from 30 patients with multiple myeloma (MM), searching for alterations in the p53 and RAS genes by a combination of polymerase chain reaction and single-strand conformation polymorphism techniques. Mutations in the p53 gene were observed in 20% (6 out of 30) of the patients, and were located in conserved sequence blocks within exons 5 and 7. These were single-nucleotide substitutions and consisted predominantly (4/6) of G:C to A:T transitions. Of the six patients with a mutated p53 gene, four were in the terminal phase of the disease. RAS gene mutations were found more frequently since they occurred in 47% (14 out of 30) of the patients. Mutations consisted of single-nucleotide substitutions, located in codons 12, 13 and 61 of either K- or N-RAS, to the exclusion of H-RAS. Moreover, one patient bore two simultaneous mutations, affecting simultaneously the K- and the N-RAS genes. RAS gene mutations were more frequently observed in patients with fulminating disease (10/15, 67%) than in patients with less aggressive forms of the disease (4/15, 26%). We also analysed genomic DNAs from 10 human myeloma cell lines, of which two bore mutations affecting codon 12 of the K-RAS gene, and one codon 12 of the N-RAS gene. The first two cell lines were obtained from freshly explanted tumor cells in which we observed identical mutations. Results presented here show that activating mutations in the RAS genes are, in MM, more frequent than those affecting the p53 gene and suggest that both events are related to terminal phases of the disease.

Mutations of the p53 gene in human myeloma cell lines.

Mutations affecting the p53 gene have been found associated with many human malignancies, but little is as yet known about multiple myeloma. We investigated p53 gene alterations in 10 human myeloma cell lines (HMCL), half of these being dependent upon exogenous interleukin 6 (IL-6) for in vitro growth, similar to freshly explanted myeloma cells. Using a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) approach, eight of the 10 HMCL were found to bear a mutated p53 gene. All the mutations were single base substitutions with a predominance of G:C to A:T transitions. There was no apparent relation between the presence of a mutation and IL-6 requirement of the cell line. Interestingly, in two cell lines (XG-2 and XG-4) the SSCP pattern showed the presence of both the wild-type and the mutated allele and, upon reverse PCR on RNA, both alleles were found to be concomitantly expressed at the RNA level. Moreover, three freshly explanted tumor samples had the same p53 gene status (mutated versus wild type) as the HMCL that were derived from them. These results show that p53 mutations are frequent in HMCL. Although no apparent relation could be evidenced with the loss of exogenous IL-6 requirement, it may prove interesting to investigate further potential relations between the presence of a mutated p53 allele and gradual autonomy for cell growth.

Nucleotide sequence polymorphism in a hotspot mutation region of the p53 gene.

By screening for mutations in the p53 coding sequence by means of single-strand conformation polymorphism (SSCP) in a series of breast tumors we detected a novel polymorphism. This change in the SSCP pattern was detected in 6.2% of the tumor DNAs analysed and implied an A to G substitution at the last base of codon 213, thus representing a neutral change. First suspecting a somatic mutation we confirmed its presence in matched sets of DNAs from normal tissues. Extending our study to a series of 60 ovarian carcinomas and 70 healthy blood donors we noticed that this polymorphism represented only 3% and 2.6% respectively. We wondered if the difference in frequency in the breast cancer population might not be related to familial breast cancer and analysed 26 DNAs from patients showing predisposition to the disease. Two patients presented this polymorphism and one corresponding kindred was analysed, revealing a mendelian mode of transmission but no correlation with the cancer phenotype.

Repertory, therapeutic indications, chemical analysis and cultural background of mineral drugs of Afghanistan.

The traditional uses of minerals drugs and chemical products for medicine were studied in Afghanistan. Twelve medicinal drugs have been identified by chemical investigations and are presented in one table with the vernacular names (in Dari, Pasto and Kati); the origins and the therapeutical uses are listed in another table with their cultural background in pre-Islamic (Greek and Indian medicines) and Islamic pharmacopoeia (Afghano-Persian and Arabian medicines). Twenty-six other mineral drugs are also mentioned.

Repertory of drugs and medicinal plants used in traditional medicine of Afghanistan.

The traditional uses of plants for medicine were studied in Afghanistan. To date, 215 medicinal plants have been identified and are presented in a table with the vernacular name (in Dari, Pashto and Kati), the geographical and ecological distribution, and the medicinal use. This study of traditional medicine demonstrates a close relationship between the kinds of medicinal plants used and pathology, and thus may serve as an indicator of the major health problems of the people.

Arrow poisons in south Asia. Part 1. Arrow poisons in ancient India.

The use of arrow poisons in ancient India is discussed. While it is possible that Mesolithic hunting communities may have applied poison to their arrows, passages in the Rg Veda and Atharva Veda indicate its use in warfare. The meaning of the word -ala, used in the Rg Veda to denote the poison smeared on the arrowheads, is examined; but the available evidence, while almost certainly excluding a mineral (arsenical) source, does not allow a conclusion to be drawn between an animal and/or plant origin. Certain hymns in the Atharva Veda point to aconite tubers as one source. Later Sanskrit (and Buddhist) literature shows that poisoned arrows continued to be used and that a second source of poison was (putrefying) snakes--a source confirmed by an account in the classical literature of Alexander the Great's campaign in western India. Detailed descriptions of the symptoms and methods of treatment of wounds caused by poisoned arrows are to be found in the Sanskrit medical literature.

[Painful stumps after digital amputations]. / Moignons douloureux après amputations digitales.

Two etiologic groups of painful digital amputation stumps may be seen, each calling for a different type of treatment. One-fourth of painful amputation stumps are due to excessive nociperception and their management usually consists of local treatment. The other three-fourths are due to thalamic sensitive deafferentation and call for neurosurgical treatment if discriminative sensitivity has not been reestablished in the painful zone. Intermittent thalamic stimulation is our choice and has led to recovery in 25 out of 26 patients who have been submitted to this type of treatment.

Cultural background of the medicinal plants of Yemen.

The study of the traditional use of medicinal plants of Yemen in the old pre-islamic and islamic pharmacopoeia has shown that: (1) the traditional medicine actually used in this country belongs to the old arabic medicine, itself similar to Greek and Indian medicines; (2) this medicine is highly original according to the great number of plants, indigenous or specific, of the Yemenite pharmacopoeia, which are not recorded in the literature, and to the high percentage of therapeutic indications belonging to Yemen which are unknown elsewhere.

[Treatment of various dyskinesias by intermittent thalamic stimulation]. / Traitement de certaines dyskinesies par stimulation thalamique intermittente.

Abnormal movements or dyskinesias are associated with hyperpathia and hyperalgesia in a number of conditions such as post amputation jumping stumps pseudothalamic syndromes following cerebro vascular accidents and in some cases of demyelinating diseases. Intermittent electrical stimulation of the specific sensory nucleus of the thalamus (I.T.S.) controls at the same time pain and dyskinesias with the same long lasting effect. In some cases where dyskinesias are associated with sensory deafferentation, but not with chronic pain or hyperpathia, the same positive effect of thalamic stimulation on the control of abnormal movements is achieved while in other cases of tremor or dyskinesias without sensory deafferentation such as parkinsonism, intention tremor etc.. the efficacy of I.T.S. is nil. Hence, discriminative sensory deaffrentation is the common link between the cases of tremor or dyskinesias that use to respond to I.T.S. which is up to now the only therapy of proven efficacy in such conditions.

[Transformation of body scheme caused by thalamic stimulation. Thalamic stimulation for painful phantom limb (author's transl)]. / Modification du schéma corporel sous stimulation thalamique. A propos des stimulations thalamiques pour membres fantômes douloureux.

Intermittent stimulation of the parvo cellular portion of the nucleus ventralis posterolateralis (VLP) was able to control both pain and phantom limb phenomenon. The authors insist upon the transformation of the "body scheme" caused by an operation which does not alter the somesthesic function. The sensorial delusion of a phantom limb is probably related to an insufficiency of sensitive information at thalamus level.

Control of dyskinesias due to sensory deafferentation by means of thalamic stimulation.

Intermittent stimulation of the parvocellular portion of the nucleus ventralis posterolateralis (V.P.L.) by means of chronically implanted electrodes and stimulus generator was performed in 124 patients for the control of chronic intractable pain. Among these, 11 showed spontaneous abnormal movements within the painful area: 6 post amputation "jumping stumps"; 4 pseudothalamic syndromes and 1 Von Benedikt's syndrome following a cerebrovascular accident. Electrical stimulation of the V.P.L. was able to control both pain and abnormal movements in all cases. The technique was applied with an equally good result in a case of choreoathetotic syndrome without pain but with severe sensory disturbances following a demyelinating process. Attempts made to control action tremor, parkinsonism and other dyskinesias not associated with sensory deafferentation in 12 cases failed. The same mechanism seems to be responsible for pain and dyskinesia in cases of sensory deafferentation, and thalamic stimulation might work as a substitute for sensory information delivered to the nucleus ventralis posterolateralis.